METTL1 and hepatocellular carcinoma: Recently, many studies have reported that METTL1 is extraordinarily expressed in a variety of cancers, including hepatocellular carcinoma, colon cancer, intrahepatic cholangiocarcinoma, lung cancer, breast cancer, glioblastoma, certain sarcomas, and acute myelogenous leukemia, which links to tumor initiation, metastasis, and chemosensitivity (9–13).